W. Skubiszak

Cavity ring-down spectrography

We propose a modified cavity ring-down spectroscopy (CRDS) technique. A pulsed broad band laser is applied as a light source while a spectrograph equipped with gated ICCD camera is used for the signal detection. The signal is simultaneously analyzed at various wavelengths within the laser line width. It allows to get the information on absorption spectra much faster and more reliable than by means of classical CRDS method with tunable laser.

Observation of ozone concentration during the solar eclipse

Abstract We report the results of measurements of ozone concentrations during the solar eclipse of 11 August 1999. The experiment was performed in Warsaw (Poland) and its surroundings. The temporal evolution of ozone concentration was measured using the differential absorption lidar (DIAL) and it was compared with results obtained by several monitoring stations measuring with other methods. In almost all cases, a drop in the ozone concentration was observed during the eclipse. Experimental data was compared with calculations done using a simple model based on NO x –O 3 chemical kinetics.

Some results on the ozone vertical distribution in atmospheric boundary layer from LIDAR and surface measurements over the Kamienczyk Valley, Poland

Abstract In this study, measurements of the vertical and temporal variations in ozone concentrations over the mountainous area during three observation periods in July 1997 and August 1998. The data used in this study were obtained from a differential measurement technique called Differential Absorption Lidar (DIAL) and from the ground-based stations at different altitudes. Many ozone profiles exhibited distinct local maxima up to 100 ppb and a large variation in mixing ratios existing in the height range between 1150–1650 m a.s.l. Ozone levels have more than doubled at about 1340 m a.s.l. as compared to higher altitudes.

Pyrylium and thiopyrylium high efficiency laser dyes

Abstract The laser emission of 34 pyrylium and 2 thiopyrylium salts under nitrogen laser excitation has been investigated and compared with that of Rhodamine 6G and Coumarin 102. Twenty compounds manifest a lasing efficiency higher than 10%. For some of them the lasing range covers more than 80 nm.

Investigation of kinetics of CH-radicals decay by cavity ring-down spectroscopy

We describe application of cavity ring-down spectroscopy (CRDS) for monitoring of CH-radicals produced by pulsed electric discharge in methane. The method provides opportunity to follow changes of concentration of the reaction product within a few microseconds.

Transverse relaxation of sodium vapour pumped by laser light

Abstract The transverse relaxation times in a sodium atomic system for different temperatures and different buffer gas pressures have been measured. Cross sections for transverse relaxation on neon atoms and in exchange collisions have been calculated. The results are σ Na-Ne =(9.1±0.5)x10 -23 cm 2 and σ ex =(1.10±0.05)x10 -14 cm 2 .

Studies of physical processes in the Earth's atmosphere

Abstract We present some optical methods of investigation of atmosphere properties: the cavity ring-down spectroscopy for detection of trace gases and different lidar techniques for remote investigation of distribution of aerosol and gaseous pollutions.

New Donor - Acceptor Chromogene Laser Dyes Generating In The Visible Spectral Range

Lasing properties of 20 new dyes generating in 480-705 nm spectral range under pulsed nitrogen laser exitation are presented. Dyes with donor - acceptor chromogene are of the main importance in the laser techniques. The best known as Coumarines, Rhodamines or Oxazines etc. are widely used for generation of a tunable laser light in a whole visible spectral range. In this paper we would like to present lasing properties of four new groups of this kind of dyes. General structures of presented groups of dyes are shown in Figures 1 (a-d). In Table 1 full chemical names as well as radicals for all the dyes are given. The methods of the chemical synthesis of these dyes were described in our previous papers.

Transverse relaxation of cesium vapour in a “strong” resonance radio frequency field☆

Abstract The fast adiabatic passage method was used to conduct measurements of the transverse relaxation times within hyperfine states of the ground state of cesium. The results of the experiment confirm the relations presented by Bouchiat for “weak” fields in spite of the fact that the field used, H 0 = 0.40 Oe is not a “weak” field. This apparent controversy is easily removed when one considers that in the presence of a rf field, atoms “see” an effective field which turns out to be a “weak” field.

Simple polychromator for multiwavelength lidar

Construction of a polichromator assigned to 9-wavelength lidar is presented. Combining the technique of narrowband interference filters and dispersion due to diffraction gratings the bandwidth of several nanometers as well as a relatively high transmission for each wavelength of interest has been achieved.